/*
 * Copyright 2007-2009 Georgina Stegmayer, Milagros Gutiérrez, Jorge Roa
 * y Milton Pividori.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package frsf.cidisi.faia.agent;

import frsf.cidisi.faia.state.AgentState;
import frsf.cidisi.faia.state.EnvironmentState;

/**
 * This class is used to know when the agent has finished. It has
 * no sense for a search based agent.
 */
public class NoAction extends Action {

    private static NoAction instance;

    private NoAction() {
    }

    public static NoAction getInstance() {
        if (instance == null) {
            instance = new NoAction();
        }

        return instance;
    }

    @Override
    public EnvironmentState execute(AgentState ast, EnvironmentState est) {
        return est;
    }

    @Override
    public String toString() {
        return "NoAction";
    }
}
